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Reissued Sept. 6, 1932 um'rsb STATES PATENT OFFICE,

ASSIGNORS, BY MESNE, ASSIGNMENTS, TO KREBS PIGMENT & COLOR CORPORATION,OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE ROS IN SOAP LAKES OIFAZO COMPOIO'NDS No Drawing. Original No. 1,772,300, dated August 5,1930, Serial No. 262,332, filed March 18, 1928. A11- plication forreissue filed March 3, 1932. Serial 1T0. 596,668.

the case of certain colors. According to prior art practice the rosinsoap has been added to the dye solution or to the commercial paste, andsubsequently converted into the metallic soap simultaneously with theprecipitation of the dyestufi, but Without specific attention to theoptimum conditions for the development of the lake. By the termdevelopment as used herein, we refer to that well known practice inmanufacturinglakes which consists essentially in heating or boiling thecolor after its various components have been incorporated one with theother.

A principal object of the present invention is to increase the yield ofthe dry product of lake pigments from a given amount of the dyestufl'semployed, i. e., to obtain a substan-- tially higher yield of pigmentfrom a given amount of dyestuff without a corresponding decrease intinctorial strength'as would be obtained in the use of an inert diluent.Another object of the invention is to increase the brilliancy andimprove the power of the lake pigment to produce an ink of superior Iprinting tone; A further object of the invention is the production oflake pigments having higher oil absorption, and other improvedproperties than those of the prior art. Other objects'will'appear as thedescription proceeds.

We have found that the use of substantial quantities of the metallicderivatives of rosin soap in lake pigments functions entirelydifferently than the smaller quantities heretofore used, when the lakeis developed in the presence of the metallic rosinate in a neutral orpreferably an alkaline medium and that according to our invention itresults in the formation of a lake substratum which does not decreasethe tinctorial strength of the final product thus indicating that itdoes not in any way act as 'a diluent. Not only thisbut the tinctorialqualities are greatly improved, for example,

a clearer, brighter masstone, more brilliant undertone and clearer tintresults, and the printing tone obtained by printing 'with an inkcontaining this material, is far superior to a similar product madeaccording to the prior art. The results were not to be expected and werein no way indicated by the prior art. The tinctorial strength may alsobe determined by measuring the covering power by means of tinting outthe pigment with white.

One of the outstanding merits of the pig- EDWARD n. ALLEN, or sumn'r.AND ALFRED SIEGEL, or HILLSIDE, NEW JERSEY,

ment prepared according to this invention or possess a highlyobjectionable bronze printing tone.

In the case of those pigments which do not give rise to a bronzyprinting tone, the

comparative difference is not marked but our invention in thisparticular does result in a higher and more glossy finish on theprinting tone as a result of the higher oil absorption and betterworking qualities of the pigment. It will beunderstood, of course, thatthis invention is not limited to the pigments referred to in theforegoing, but other pigments may be similarly modi- The rosin soap isincorporated with the azo compound, preferably prior to its filtration,and the rosin soap is converted into a metallic soap simultaneously withthe precipitation of the azo compound.

It is to be understood that the term rosin soap as used in the followingexamples and elsewhere in this application, refers to rosinates or themetallic derivatives of rosin. The expression rosin soap as used hereincovers the soap obtained from resins containingsubstantial amounts ofabi'etic acid.

As specific examples of procedure, in ac- ,cordance with our invention,the following will serve, but it is to be understood that these examplesare for illustrative purposes only and are not to be taken in any Way aslimitations of our invention.

Example I A solution of the sodium salt of 2-naphthlyamine l-sulphonicacid corresponding to 111.5 parts of the free acid, is diazotized in theusual manner with 37.75 parts of sodium' nitrite and 204 parts ofmuriatic acid B. The major part of the excess mineral acid is thenremoved from the insoluble diazo body by means of washing. In a separatecontainer a solution of 80 parts of betanaphthol and parts of causticsoda is-prepared and made to a volume corresponding to approximately2500 parts of water. After'the temperature of this solu-' To a solutionof 26.5 parts of caustic soda in 325 parts of water there is added 75parts of rosin. The volume is then brought to the equivalent ofapproximately 1900 parts of water, the preparation boiled to completethe saponification. This preparation of rosin soap is then run into thecharge of the azo dye, described above, and the temperature and volumeof the combining solutions so adjusted that the temperature of theresulting charge does not drop below 30 C. 7

It will be evident from the above figures that the reaction masscontains at this point alkali equal to 0.75 mol NaOH for each mol ofdyestufl' produced. The charge is then precipitated with a solution of240 parts of, barium chloride in 5,000

- parts of water, brought to a boil in order to develop thelake, and theproduct then Washed, filtered, dried, and ground in the usual manner.

The yield is approximately 315 parts of dry product compared with 225parts in a charge prepared without rosin soap. The resin soap lake isequal in covering power (determined by tinting in white) to the productobtained without the use of rosin soap, and is equal in this respect-tothe ordinary commercial barium lithol toner. It is much brighter inshade, cleaner in tone, and when ground into litho varnish to produce aprinting ink, the latter product gives a print which possesses a bright,firey, bronge-iree tone not hitherto possible from the tonersof-thelithol red class. In other words, this new product possesses thestrength of a toner and the printing qualities of a lake.

Emample II V The procedure is the same as that-described in Example Iexcept that instead of 26.5 parts of caustic soda in the rosin, onlysufficient of this alkali is used to convert the rosin into a. soap. Theproduct so obtained is a pigment much lighter and yellower than thatdescribed under Example I.

The yield is equivalent to that obtained in Example I. The onlydifference between this example and the preceding one is that in ExampleII the dye is developed in the presence of a lesser amount of alkaliresulting Y in a pigment of much lighter and yellower shade and thisexample illustrates the effect of the absence of alkali. during thedevelopment of the pigment. 1

Example III Y The same procedure is used as in Example I except thatparts of rosin is prepared as rosin soap instead of 75. parts as inExample I, and 88 parts of calcium chloride are used to effect theprecipitation instead of the 240 parts of barium chloride. It will beseen when compared with Example I that the rechloride and thedevelopment contains a still larger amount of alkali.

ordinary calcium lithol red used in the trade.

The yield is approximately 275 parts of dry powder compared with 200parts obtained without the rosin soap. The superiority of the rosin soaplake is similiar in this case to that described in Example I.

Ema/ripple I V The procedure is the same as that described in ExampleIII except that'the rosin soap isaddcd to the azo compound at the boil,and the precipitation and development of the color is'carried out atthis temperature. The pigment obtained by this procedure is camparablein blueness of tone to that described in vI)RP24 5, 747 (Friedlander x,page 936) The yield isequivalent to that of Example III. The product ismaroon. orssclaret in action mass prior-to the addition of calcium Theproduct so obtained corresponds in depth of shade to the shade, whereasthat described in Example III 7 is bluish red. The product possesses thesame qualities as to power to produce an ink yielding a bronzelessprinting tone.

I Emample V- A solution of 52.25 parts of. the sodium salt ofparatoluidinemetasulphonic acid (CH SO NH =1.: 3 4) is diazotized with18 parts of nitrite of soda and'65 parts of 20 B. muratic acid. 50 partsof betaoxynaphthoic acid (OH:COOH=2:3) is dis- 7 solved in a solution ofparts of sodium hydroxide in 400 parts of water. To this is then added54 parts of soda ash in 300 parts of water.

In a separate container 22.5 parts of rosin is added to a solution of3.6 parts of sodium hydroxide in 300 parts of water, and the solu tionboiled to effect the formation of the rosin soap. This solution of rosinsoap is now added to the above described solution of beta-oxynaphthoicacid, the volume brought to the equal of 1250 parts of water, 11.5 partspara soap added, and the temperature adjusted to C. The above describeddiazo preparation is then run in whereupon the azo coupling proceedsquickly and to good completion. The charge is adjusted to neutrality,the volume brought to the equivalent of 25,000 parts of water, heated to57 (1, and the color precipitated with a solution con taining 86 partsof calcium chloride. The charge is then brought to the boil, anddigested at this temperature for 15 minutes, after which it is washed,filtered, and dried in the usual manner. mately 146 parts of pigmentcompared with 112 parts in a charge carried out'inexactly' the same waybut without the rosin. The rosin soap lake is equalin strength to thenormal product and is superior to it in richness of shade, clarity oftone, and freedom from bronze on the printing tone obtained fromprinting inks prepared from it.

Example VI is diazotized with 18 parts of nitrite of soda and 65 partsof 30 B. muriatic acid.

parts of beta-oxynaphthoic acid are dissolved in a solution of 21 partstion is adjusted to 40 C. and the above de-' scribed diazo preparationis then run in whereupon the azo coupling proceeds quickly and to goodcompletion. After stirring a short time the dyestutf is filtered.

The soda salt dye paste is then reslurried in 25,000 parts of water at40 C. To this are added 11.5

parts of para soap in 00 parts of Water.

In a separate container 6 parts of rosin are added to a solution of 1.6parts of sodium hydroxide in 400 parts water, and the solution boileduntil the formation of the soluble rosin sodium salt is complete. Thisrosin soap solution is then added to the dye solution and thetemperatureadjusted to 40 C. and stirred 15 minutes.

The yield is .approxi- .boiland digested at this temperature for hour,after which it is washed, filtered, and

dried in the usual manner. The yield is approximately 127 parts ofpigment compared with 120 parts in a charge carried out in exactly thesame way but without the rosin. The rosin soap as-calcium rosinate is5.51 per cent of the finished dry pigment color.

Example VII A pigment color is prepared in a manner similar to the aboveand from slmilar ingre- ,dients, but the amount of calcium rosinate isincreased to 11.1 per cent in the finished dry pigment color. The rosinsoap solution is prepared as follows:

13' parts rosin are added to a solution 2.6 parts of sodium hydroxide in600 partsof water and the solution boiled until the for mation of thesoluble rosin sodium salt is complete. This is then added to thedyestufi' as in Example VI. The alkalinity during the development is.the same as in the preceding example. The yield'is approximately 134parts of pigment as compared with 120 parts in a charge carried out inexactly the same way but without the rosin.

The calcium rosinate in this case comprises 11.1 per cent of thefinished dry pigment color.

E wample VIII A solution of the sodium salt of 2-naphthylamin'el-sulphonic acid corresponding to 111.5 parts of the free acid, isdiazotized in the usual manner with 39 parts of sodium nitrite and 204parts of 20 B. muriatic acid.

.In a separate container a solution of 80 parts of beta naphthol and 36parts of caustic soda is prepared and made to a volume corresponding toapproximately 2500 parts. After the temperature of this solution hasbeen adjusted to 25 C. the diazo suspension, formed as indicated above,is introduced into the beta naphthol solution. When one-half of thediazo suspension has beenadded a solution of 15 parts of caustic sodadissolved V in 40. parts of water is added and the coupling completed.The coupling proceeds rapidly and to good completion. The volume is thenmade to 13,000 parts and heated to 40 C. in 15 minutes. 1

In a separate container 150 parts f rosin are added to a solution of 35parts o caustic soda and 2100 parts of water and the preparation boiledto complete'the saponification. This preparation of the rosin-is thenrun into the charge of the azo dye,- described above,

and the temperature of the combined solutions adjusted to 40? C. It willbe evident from the above figures that the reaction mass contains atthis point free caustic alkali equal to 1.75 mols NaOH for each mol ofdyestuif produced. In a separate'container 270 parts 1 of bariumchloride crystals are dissolved in product is then washed, filtered,anddried and ground in the usual manner.

The yield is approximately 397.5 parts of dry pigment color as comparedwith 240 parts actually obtained in a charge prepared in a similarmanner but without rosin soap. The amount of barium rosinate comprisesper cent of the finished dry pigment color.

Example [X P I I The procedure is the same as that described in ExampleVIII except that the rosin soap and barium chloride are increased asfollows:

y 250 parts of rosin are added to a solution of46 parts of sodiumhydroxide and 2500 parts of water and boiled to effect complete.

saponification. The free alkali in the reactionmass is thereby increasedto 1.6 mols per mol of dyestufi. The barium chloride is increased to 310'parts in order to take care of the excess rosin. The yield isapproximately 498 parts of dry pigment color as com ared with 240parts-actually obtained in a c arge prepared without-rosin soap. Theincrease in yield is 258 parts, the barium rosinate comprising 5 1.9 percent of the dry pigment color.-

Example X I f The procedure is the same as that described v-1n ExampleVIIIexcept the rosin soap and barium chloride areincreased as follows:

350 parts ofrosin areadded to a solution of 58'parts of sodium hydroxideand 3200 parts of water and boiled to efiect complete saponification.The free alkali in the reaction mass is thereby increased to 1.6 molsper mol of dyestufi. The barium chloride is increased to 350=parts inorder to take care of the excess rosin. The yield is approximately 590parts of dry pigment color as compared with. 240 parts actually obtainedin a charge without rosin'soap. The increase in yield is 350 parts, thebarium rosinate comprising 59.33

per cent of the dry pigment color.

Thepigment forming azo compounds given in theabove examples belong tothe group of acidic mono-azo compounds, the sodium salts of which aredifiicultl'y soluble in water,

and these areparticularly adapted to'form according to our inventionlakes or toners on development with roslnatesin whlch'the rosin acts asa non-diluting substratum. Specifically these compounds are the azocompounds derived from 2-naphthylamine l-sulphonic acid and betanaphthol (known in the trade as Lithol Red) and fromparatoluidinemetasulphonic acid and beta-oxynaphthoic acid (known in thetrade as Lithol Rubine) Although we preferably use the metallicderivatives of barium or calcium, or both, we may-also use strontium,magnesium, lead or copper or any of the metals which form substantiallyinsoluble metallic soaps with rosin.

Although instances of the use of small amounts of rosin soap asadispersing agent are known, this invention is distinguished by the factthat we combine a substantial amount we may incorporate as little asapproximate- 1y 5 per cent of rosin soap and as high as 50 per cent oreven' greater proportion, the preferred range is from 15'to 30 per cent.

It will be understood, of course, that we do not intend to limitourselves to the addition of,

the rosin soap to the azo compounds under the exact conditions specifiedin the foregoing examples for the reason that in some cases it ma be ofsome advantage in order to secure certaln tints or shades to add aportion of the rosin soap during the coupling, or at.

some other step in the process. We have found that the desired resultsare obtainable by the development of the metallic salt of the dyestufiin the presence of the insoluble me tallic rosinate, preferably underalkaline conditions. I

A particular advantage in the use of the pigment prepared according toour invention is in the matter of the bright glossy I rinting toneobtained therefrom. The

ronziness of the rinting tone ordinarily present in colors of this klndis eliminated. For exam 1e, if equal parts of rosin soap lake and hthovarnish of #1 grade (bodied linseed oil are-ground in the ordinarymanner on a t ree roll ink mill, there is obtained a printing inkossessing heavier body, by virtue of the big er oil absorption of thepigment, than is obtainable with a pigment made inthe ordinary manner.In place of the litho varnish, other commercial vehicles or combinationvehicles may be used. The greatest superiority, however, of this ink isthat the resulting printing. tone is dis- -tinc'tly superior to an inkmade from an ordinary pigment, in the matter of gloss and brilliance, aproperty which is prethe better dispersion of the pigment with the oil.I

By the term metallic rosin soap, as used harem, we mean the metal saltsof the rosin case of the alkali metals are limit ourselves to thespecific embodiments thereof except as indicated in the appended claims.

We claim:

' 1. A substantially oil and water insoluble lake which comprises aninsoluble metallic salt of an azo dyestufl' and from 15% to 50% of a nondiluting substratumcomprising a substantiallyinsoluble metallicrosinate, said lake having'the characteristic of producing a clear,bright, non-bronzy tone.

2. A substantially oil and Water insoluble lake which comprises aninsoluble metallic salt of an azo dyestufi of acidic character and from15% to 50% of a nondiluting substratum comprising a substantiallyinsoluble metallic rosinate inadefrom a metal of the group comprisingthe alkaline earth metals, copper, lead and magnesium, said lake havingthe characteristic of producing a clear, bright, non-bronzy tone.

3. A substantially oil and water insoluble lake which comprises theinsoluble metallic salt'of an azo dyestuff and from 15% to 50% of aninsoluble metallic rosinate, said lake having the characteristic ofproducing a clear, bright, non-bronzy tone.

4:. A substantially oil and water insoluble lake which comprises aninsoluble metallic salt of an azo dyestutf and from 15% to 50% of anon-diluting substratum comprlsing an alkaline earth metal rosin ate,said lake having the characteristic of producing aclear bright,non-bronzy tone.

5. A substantially oil and water insoluble lake whichcomprises aninsoluble rosinate and an insoluble metallic salt of the dyestufiobtainable by coupling beta naphthol with diazotized 2-naphthylamineI-sulphonic acid, said lake having been formed by developing it underalkaline conditions, said lake 113V.

ing the characteristic of producing a clear, bright, non-bronzy tone andsaid 10811121178 being present in a proportion of about 15% to 50% ofthe finished product.

6. A substantially oil and water insoluble lake which comprises analkaline earth metal rosinate and an alkaline earthmetal salt of thedyestuff obtainable, by coupling beta naphthol with diazotized2-naphthylamine 1- sulphonic acid, said lake having been formed bydeveloping it in alkaline conditions, Sald rosinate being present in-aproportion of I about 15% to 30%. of the finished product,

and said lake having the characteristic of producing a clear, bright,non-bronzy tone.

7. A substantially oil and Water insoluble acid and heating "said lakehaving been formed by developing it in alkaline conditions, saidrosinate being presentin a proportion of about 15% to of the finishedproduct, and said lake having the characteristic of producing a clear,bright, non-bronzy tone.

I 9. In a process of preparing a substantially oil and water insolublelake of an acidic azo dyestufl, the steps of combining an insolublemetallic salt of an azo dye of acidic character with an insolublemetallic rosinate in an aqueous medium, and heating the aqueoussuspension of said dye salt and rosinate-in the presence of free alkalito develop the lake.

10. The process of preparing a substantially oil and water insolublelake which produces clear, bright, non-bronzy tones, which comprisespreparing an aqueoussuspension comprising an alkaline earth metalrosinate present ina proportion and an alkaline earth metal salt of theazo dyestufi' obtained by coupling beta naphthol with diazotized2-na'phthylamine l-sulphonic the mixture in the presence of free alkalito develop the lake, said rosinate being present in the proportion ofabout to 50% of the finished product.

11. The process of preparing a substantially oil and water insolublelake which produces clear, bright, non-bronzy tones, which comprisespreparing an aqueous suspension comprising an alkaline earth metalroslnate and an alkaline earth metal salt of the azo dyestuff obtainedbycoupling beta naphthol with diazotized 2-n aphthylamine l-sulphonicacid, but heating the mixture in the presence of at least one-haltmolecular amount of free causticior each molecular amount of thedyestuft' to develop the lake, said rosinate being present in theproportion of about 15% to 30% of the finished product.

12. The process of preparing a substantiallv oil and water insolublelake which produces clear, bright, non-bronzy tones, whlch comprisespreparing an aqueous suspension comprising an alkaline earth metalrosinate and an alkaline earth metal salt of the azonlye stuff obtainedby coupling beta-oxynaphthoic acid with diazotizedp-toluidine-metasulphonic acid (CH SO: :NH 1:3: 4), and heating saidaqueous suspension in a nonacidic condition to develop the lake, saidrosinate being present in the proportion of about 15% .to of thefinished product.

13. The process of preparing a substantial ly oil and water insolublelake which produces clear, bright, non-bronzy tones, which comprisespreparing an aqueous suspension comprising an alkaline earth metalrosinate and an alkaline earth metal salt of the azo dyestufl obtainedby coupling beta-oxynaphthoic acid with diazotizedptolui'cline-metasulphonic acid (CH SO NH =1:3:4)', and heating themixture in the presence of at least one-half molecular amount 'of freecaustic for each molecular amount of the dyestufi to de 'velop the lake,said rosinate being present in the proportion of about 15% to 30% of thefinished product.

In witness whereof, we afiix oursignatures.

EDWARD R. ALLEN. ALFRED SIEGEL.

